Signal system for telephone-exchanges



(No Model.) 2 Sheetsheet 1. W. S. JOHNSON 8v C. L. EORTIER. SIGNAL SYSTEM FOR TELEPHONE EXCHANGES.

Patented Feb. 9, 1886.

(No Model.) 2 Sheets--Sheet 2.

W. S. JOHNSON & G. L. FORTIER. SEGNAL SYSTEM EOE TELEPHONE EXCHANGES.

No. 335,934. Patented Feb. 9, 1886.

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UNITED STATES PATENT OEEIcEo W'ARREN S. JOHNSON, OF VVHITEVATER, AND CHARLES L. FORTIER, OF MILVAUKEE, YVISOONSIN.

SGNAL SYSTEM FOR TELEPHONE-EXCHANGES.

C,5PLCIFICJATIOZtl' forming part of Letters Patent No. 385,934, dated February 9, 1886.

(No model.)

To all whom t may concern.'

Beit known that we, W ARREN S. JonNsoN, of lVhitewater, in the county of Valworth and State of Wisconsin, and CHARLES L. Fon- 'rIER, of Milwaukee, inthe county 0f Milwaukee, and in the State of Wisconsin, have invented certain new and useful improvements in Signal Systems for Telephone-Exchanges; and we do hereby declare that the following is a full, clear, and exact description thereof.

Our invention relates particularly to signal systems for telephone-exchanges, and will be described hereinafter.

In the drawings, Figure 'l is a diagrammatic View, partly in elevation and section, representing one forni of our invention; and Fig. 2 is a similar view representing` modifications in construction.

A is a magneto-electric machine, the armature of which is revolved by a train of gearing consisting of pinions and wheels a b c d e and a rack-bar, j'. A ratchet-wheel, g, is keyed on the shaft oi' wheel d and pinion e, and a pawl, h, that is pivoted to wheel d, hangs down against the periphery of wheel g, so as to engage with its teeth. The wheel d turns loosely on its shaft. The rack-barf slides in suitable bearings, fj", and terminates at one end in a piston, k, the head of which is fitted in cylinder k. rThe head k2 of cylinder k is made with perforations through it, which allow the air to pass freely in and out on that side of the piston-head, and a spring, l, is interposed between the piston-head and cylinder-head k2, which serves to force the piston-head in after the pressure that forces it outward ceases. Cylinder k is connected by a pipe or tube, m, with a hollow stand, B, that leads to a compressed-air reservoir, and the upper part of this stand is provided with a valve-chamber, B', having two seats for the valve O, which latter has a stein, C', that passes up through an opening, O2, in the valve chamber B', through an opening in akey-lever, D, and up toaspring, D', to which it is secured. A collar,

D2, is secured onto the stein C beneath lever D, and a spring, E, serves to draw this end oi' the lever D down, so as to hold valve C tightly closed upon its lower seat, and thus close the outlet of the compressed-air reservoir. The

key-lever D is fulcrumed in a stand, E, and on its end opposite that which carries the valve-stem may be provided with a button, El. Beneath this end of the key-lever is a contactpost, F, from which a wire leads 'to a magnetostrip, F, ou the switch-board, which in turn may be electrically connected with the subscribers bells, (one of which is shown at G,`) when desired. The key-lever is electrically connected to one end of the coil of the armature of the magneto-electric machine A, the other end of said coil being connected, as usual, with the core of said armature, and thence to ground. rlhe valve O maybe suitably faced with leather or rubber to make it air-tight.

The operation of our device is as follows: The parts are arranged in any convenient relations to each other, and when the apparatus is not in action the head of the piston 7c is held by the spring Z close up against the inlet end of the cylinder k. The valve C is held tightly down upon its lower seat by spring E and the key-lever. Now, suppose the bell Gl is to be rung. rlhe button E2 is pressed upon slightly and the valve C is lifted from its lower seat up against its upper seat, opening coinrnunication from the compressed-air reservoir to cylinder 7a, and this air, by forcing out the piston k, will cause the rack-bar to set the train of gearing c d c b in motion and revolve the armature. Now, the button E" may be further depressed until contact is made between the key-lever D and post F, when whatever distant bell is in circuit will be rung. The rings may be intermitted by making and breaking contact between the lever and post without interrupting the flow of compressed air to the cylinder, for the strength of spring D is such that by depressing the button end of lever D a certain distance the valve C may be lifted from its lower seat toits upper seat, and then the resistance of spring D will become so great that it will require an extra eX- ertion to depress the button end of the key enough to produce contact with post F, and therefore while the weight of the hand is sufiicient to raise valve C an additional pressure will be necessary to complete the circuit. After the bell has been rung, and as soon as IOO the button is released, the valve C will drop, closing the reservoir-outlet and opening the exhaust-outlet O2, so that the air can escape freely as the spring Z forces the piston back.

It is obvious that our device may be variously modified without departing from the spirit of our invention; for instance, instead of a cylinder and piston, abellows-like expansible chamber similar to that shown in Fig. 2 may be used, and, further, a different style of key-lever and connections may be used. Therefore we do not mean to limit ourselves to the exact construction of the parts as shown.

Though we have described ka circuit from the magneto-electric machine A through the key-lever to switchboard, we find in practice that the magneto-electric machine and switchboard may be directly connected, and when this is done the spring D may be dispensed with and the key-lever connected directly with valve-stem C', all as shown in Fig. 2, since the pulsations of air in the eXpansible chamber occasioned by depressing and releasing the key are usually sufficient to produce short signal rings of the distant bell.

In said Fig. 2 we have designated the outer movable wall of the eXpansible chamber as k, to correspond with the piston-head shown in Fig. l, and consequently placed the springl outside of the same, dispensing with the extra head k2, which is unnecessary in this form of device.

Our device is adapted for use with any of the switch-boards as at present constructed.

Having thus fully described our invention, what we claim as new, and desire to secure by Letters Patent, is-

1. In a system for signaling, the combination, with the central magneto-electric-machine armature, of a train of gearing, a compressed-airv reservoir connected therewith, a valve, and a key-lever for operating the valve, as set forth.-

2. The combination, with the compressedair reservor and its valve, of the cylinder, piston, retracting-spring, intermediate gearing, and the magneto-electric machine, as set forth.

3. The combination, with the reservoir, cylinder, and piston, of the stand having doubleseated valve-chamber and exhaustoutlet, the valve, key-lever, and its springs and electrical connections, as set forth.

4. In a'system for ringing magnetobells, the combination, with, a central magnetoelectricmachine armature, of an expansible chamber connected therewith, and a connection for admitting fluid under pressure into the expansible chamber. Y

5. A chamber adapted for expansion under luid-pressure, and to contract when thepressure is removed, in combination with. a magneto-electric machine and intermediate gearing connecting one of the walls of the eXpan sible chamber with the magneto-electric-machine armature, whereby the expansion of the chamber will causev the armature to revolve, as and for the purpose set forth.

In testimony that we claim the foregoing :we have hereunto set our hands, at Milwaukee, in the county of Milwaukee and State of Wisconsin, in the presence of two witnesses.

WARREN S. JOHNSON. CHARLES L. FORTIER. Witnesses:

S. S. SToU'r, H. J. FoRsY'rH. 

